The tune, burned-out Billy tells a disk jockey, is "crap." But "Christmas is All Around" is undeniably catchy and irresistibly sweet, in a charming, self-conscious way. This being the movies, the song tops the charts – and invades the hearts of seemingly everyone in the U.K. just in time to play Cupid for the holiday.

The song subplot echoes the odyssey of "Love Actually," the cinematic version of an earworm: The flick wraps its gooey arm around you and won't stop hugging.

"Love Actually" extends its hold on fans – admitted and otherwise – with a 10-minute sequel of sorts making its U.S. debut May 25 on NBC as part of the network’s Red Nose Day programming. Like the fundraiser, in which folks are encouraged to don a clown's red nose for the day, "Love Actually," embraces the spirit of taking a chance on being silly in the name of love.

Comic Relief's Red Nose Day, which backs efforts to help children around the world, is a longtime British tradition, much like rooting for a Christmastime No. 1 hit. The NBC broadcast marks the third year of the U.S. version, with the latest special to be hosted by Chris Hardwick.

But the star attraction is the "Love Actually" short in which writer-director Richard Curtis queues up the cue cards again to update the stories of multiple characters from the film.

Expect glimpses of Nighy, Keira Knightley, Colin Firth, Liam Neeson, Martine McCutcheon and Rowan Atkinson, among others. Also on tap is a return appearance Hugh Grant, whose casting as a gravitas-free, dance-happy prime minister doesn't seem as silly as it did 14 years ago.

Neither do his character's words, spoken at the beginning of a movie that burrowed into the popular consciousness by emanating unrelenting good will: "It seems to me that love is everywhere. Often it's not particularly dignified or newsworthy, but it's always there.